SLAAEO5 September   2024 MSPM0C1103 , MSPM0C1103-Q1 , MSPM0C1104 , MSPM0C1104-Q1 , MSPM0G1105 , MSPM0G1106 , MSPM0G1107 , MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G3105 , MSPM0G3105-Q1 , MSPM0G3106 , MSPM0G3106-Q1 , MSPM0G3107 , MSPM0G3107-Q1 , MSPM0G3505 , MSPM0G3505-Q1 , MSPM0G3506 , MSPM0G3506-Q1 , MSPM0G3507 , MSPM0G3507-Q1 , MSPM0L1105

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction to the Debug Subsystem and MSPM0
    1. 1.1 Access Ports of MSPM0
      1. 1.1.1 Advance High-Performance Bus Access Port
      2. 1.1.2 Configuration Access Port
      3. 1.1.3 Security Access Port
      4. 1.1.4 EnergyTrace Access Port
      5. 1.1.5 Power Access Port
    2. 1.2 Behaviors With the MSPM0 in a Blank/Low-Power State
  5. 2Proper SWD Initialization Sequence
  6. 3PWR-AP
    1. 3.1 Enabling Low-Power Mode Debugging With MSPM0
    2. 3.2 Modifying the Reset Behavior of MSPM0
      1. 3.2.1 Wait for Debug
      2. 3.2.2 Halt on Reset
      3. 3.2.3 INRST Behavior
    3. 3.3 Register View
  7. 4SEC-AP
    1. 4.1 DSSM Commands
      1. 4.1.1 Factory Reset
      2. 4.1.2 Mass Erase
      3. 4.1.3 Password Authentication
      4. 4.1.4 Data Exchange
      5. 4.1.5 Wait for Debug
      6. 4.1.6 Custom DSSM Command
    2. 4.2 DSSM Flow
    3. 4.3 Register View
  8. 5Understanding Flash in MSPM0
    1. 5.1 Protection of Flash Memory Across MSPM0
    2. 5.2 Clearing the STATCMD Register
    3. 5.3 Ideal Programming Flow for MSPM0
  9. 6The Resets of MSPM0
  10. 7Summary
  11. 8References

2 Proper SWD Initialization Sequence

MSPM0 uses the Arm® M0+ core, allowing the user to follow the procedure described by Arm to switch the device from JTAG to SWD.

Upon executing the described sequence by Arm to switch from JTAG to SWD, the Wake Logic unit seen in sends a wake-up request to the device allowing the IDCODE to be read regardless of any low-power state the device could be in and for the access ports to be available as well.

It is best practice to have the SWJ-DP state machine in a known state before beginning any operation. Before going in between states, perform a line reset then begin the SWD to JTAG sequence, this is to ensure the lines are in reset and have been initialized to a known state. Then perform the line reset and then JTAG to SWD sequence, upon doing so the Wake Logic unit sends a wake-up signal to the CPU allowing the IDCODE to be read even when the device is in SHUTDOWN mode. To see what should be done when implementing the SWD initialization sequence, see the flow chart in Figure 2-1.

MSPM0 SWD Initialization Sequence Figure 2-1 MSPM0 SWD Initialization Sequence